[en] Rare-earth elements including Y, Er and Sc were added to AlTi₃ for stabilizing the L1₂ ordered crystal structure, as predicted by the AB₃ structure map. The crystal structure and phase composition in the AlTi₃ alloys were studied by electron microprobe analysis, X-ray diffraction and TEM. The solubility limit of the rare-earth elements were determined and correlated with the atomic size factor. The results obtained so far indicate that rare-earth additions are unable to change the crystal structure of AlTi₃ from DO₁₉ to L1₂. The inability to stabilize the L1₂ structure demonstrates the need to characterize the structure map domains with a further period-dependent parameter

[en] Short communication

[en] Laser-induced fluorescence line-narrowing has revealed that the emission properties of Nd³⁺ in various glasses are strongly dependent on the nature of the site. In a mixed anion glass, the multiplicity of ligand combinations causes additional complications. The spectral and kinetic manifestations of these are presented and discussed

[en] We present measurements of the 4G7/2 emission lifetime for 26 Nd-doped materials. A model of nonradiative decay based on dipole-dipole energy transfer is developed and found to be supported by our data

No abstract available

[en] Incramute is a high damping alloy with a nominal composition (weight percent) of 45 Mn-53Cu-2Al. This alloy exhibits a specific damping capacity as high as 68% where the SDC is defined as the ratio of the energy lost to the maximum vibrational energy stored per cycle per unit volume. This paper discusses how the high damping character of Incramute is formed by a solution heat treatment and aging sequence which develops a chemically modulated microstructure with Mn-rich regions

[en] Effect of Sn, Gd impurities in Si and Si impurity in Gd on half-width and form of IR absorption bands of hydrogenic centers (HC) was studied. Spectra were investigated within 2-77K temperature range. Sn content varied within 2·10¹⁸-2·10¹⁹ limits, while Gd content -8·10¹⁴-2·10¹⁸cm^-3. The conducted investigation of temperature dependence of absorption band half-widthes showed, that widening was heterogeneous one, band half width did not practically change within 3-45K temperature range. Increase of covalent radius of impurity elements at equal concentrations resulted in increase of HC heterogeneous widening in ceramics. The authors consider, that presence of chaotic deformation fields, resulted from nonconformity of covalent radii of matrix and impurity, is the main reason of heterogeneous widening of HC absorption lines in covalent crystals with electrically passive impurities

[en] A new light source has been proposed and studied for atomic absorption analysis, combining a means for high-temperature atomization of the substance and a light-through source with elevated brightness. The device is shown to be suitable for the quantitative analysis of quartz glasses alloyed with titanium and europium without any preliminary acid decomposition of the samples. Determination limit of the above elements from a weight amount of 1 mg is 1.10^-3% and the relative standart error is within 0.02 - 0.06

[en] Uniform upconversion in erbium-doped silicate glasses is investigated as a function of glass composition, concentration, and fabrication method. Comparisons of upconversion coefficients are made among soda lime silicate and aluminosilicate bulk glasses and soda lime silicate waveguides. Comparisons are also made with studies performed by other researchers. The results indicate that both the composition and the preparation method of the glass affect the value of the upconversion coefficient, with as much as a factor-of-4 variation observed at fixed Er³⁺ concentration. Values of the upconversion coefficient are found to be consistent with the Foerster endash Dexter microscopic model. copyright 1997 Optical Society of America

[en] The superposition model is applied to the calculation of intrinsic parameters for each europium-ligand distance in LaCl₃, LaAlO₃, La₂O₃ and La₂O₂S. These parameters allow one to draw conclusions regarding the covalency of these compounds and, in some cases, to characterize the europium-ligand bonding. On the other hand, for weakly covalent compounds, the sigma* parameters may be determined by the angular overlap model